1. Field of the Invention
The present invention relates to air pumps and, more particularly, to a two-way mounting mode air pump, which can be selectively arranged in either of two positions to pump air into or out of an inflatable object.
2. Description of the Related Art
When inflating or deflating a big inflatable object, for example, an air mattress, air pump means may be used. There are inflatable mattresses with affixed air pump means. FIG. 1 illustrates a similar prior art design. As illustrated, a mount 7 is affixed to the wall panel of the air mattress (not shown). The mount 7 has a fixed battery case 72, a mounting hole 71, and power output contacts 73 disposed in the mounting hole 71 for output of power from the battery set in the battery case 72. A motor pump 8 is insertable in the mounting hole 71. The motor pump 8 has an air inlet 82 in one end, and air outlet 83 in the other end, and power input contacts 81 at the periphery. The motor pump 8 can be inserted into the mounting hole 71 in a first position to pump outside air into the air mattress, or in a second position to pump inside air out of the air mattress. To use it, the user needs to rotate the motor pump 8 in the mounting hole 71 to move the power input contacts 81 into contact with the power output contacts 73 respectively. After each use, the user needs to rotate the motor pump 8 again to disconnect the power input contacts 81 from the power output contacts 73. This operating procedure is complicated. When rotating the motor pump 8, it is difficult to control the accurate angle of rotation. If the motor pump 8 is not accurately rotated into position, battery power supply cannot be transmitted to the motor pump 8. Positioning means may be provided to ensure accurate positioning of the motor pump 8 in the mounting hole 71. However, the installation of such positioning means greatly increases the cost. Further, because the battery case 72 is fixedly installed in the mount 7, it cannot be detached from the mount 7 for use with the motor pump 8 in other places.